目前好多的微信活动都有一些抽奖活动，其中就有跑马灯。
<!DOCTYPE html>
<html>
<head>
<title>跑马灯效果</title>
<style>
table .pao{
border:1px solid #e5e5e5;
padding:10px 20px;
}
table .on{
border-color:red;
color:red;
}
</style>
<script>
window.onload = function(){
var paomadeng = {
currentIndex : 1, //当前索引
indexCount : 12, //个数
timer : 0, //定时器
currentCycle : 0, //当前圈数
cycles : 4, //跑的圈数
speed : 400, //速度，即定时器的时间间隔
key : 0, //钥匙,随机数
btn : 0, //触发按钮
classPrefix : "pao-", //元素类名class前缀
reset : function(){
//触发对象
paomadeng.btn = this;
paomadeng.btn.style.display = "none";
clearInterval(paomadeng.timer);
paomadeng.currentCycle = 0;
paomadeng.speed = 400;
paomadeng.key = Math.ceil(Math.random() * paomadeng.indexCount);
console.log("key:" + paomadeng.key);
paomadeng.run();
},
run : function(){
console.log("speed:" + paomadeng.speed);
var before = paomadeng.currentIndex == 1 ? paomadeng.indexCount : paomadeng.currentIndex - 1;
//设置上一索引的类名
var beforeNode = document.getElementsByClassName(paomadeng.classPrefix + before)[0];
var beforeClassNewName = beforeNode.className.replace("on","");
beforeNode.className = beforeClassNewName;
//设置当前索引的类名
var currentNode = document.getElementsByClassName(paomadeng.classPrefix + paomadeng.currentIndex)[0];
currentNode.className += " on"; //注意前面有空格
paomadeng.upSpeed();
paomadeng.downSpeed();
paomadeng.currentIndex += 1;
paomadeng.currentIndex = paomadeng.currentIndex > paomadeng.indexCount ? 1: paomadeng.currentIndex;
},
//加速
upSpeed : function(){
//前2圈且speed>100时加速
if(paomadeng.currentCycle < 2 && paomadeng.speed > 100){
paomadeng.speed -= 5 * paomadeng.currentIndex ;
paomadeng.stop();
paomadeng.start();
}
},
//增加圈数 并 减速
downSpeed : function(){
//增加圈数
if(paomadeng.currentIndex == paomadeng.indexCount){
paomadeng.currentCycle += 1;
}
//如果当前所跑圈数小于总圈数-1 并且 速度小于400，那么减速
if(paomadeng.currentCycle > paomadeng.cycles-1 && paomadeng.speed < 400){
paomadeng.speed += 20;
paomadeng.stop();
paomadeng.start();
}
//如果当前所跑圈数大于总圈数 且 索引值等于key，那么停止奔跑
if(paomadeng.currentCycle > paomadeng.cycles && paomadeng.currentIndex == paomadeng.key){
paomadeng.stop();
paomadeng.showPrize();
}
},
stop : function(){
clearInterval(paomadeng.timer);
},
start : function(){
paomadeng.timer = setInterval(paomadeng.run , paomadeng.speed);
},
showPrize : function(){
//过一会再显示提示信息
setTimeout(function(){
alert("恭喜，你中了" + paomadeng.key + "等奖");
paomadeng.btn.style.display = "block";
},700);
}
};
document.getElementById("startPao").onclick= paomadeng.reset;
};
</script>
</head>
<body>
<div class="container">
<table>
<tr>
<td class="pao pao-1">1</td>
<td class="pao pao-2">2</td>
<td class="pao pao-3">3</td>
<td class="pao pao-4">4</td>
</tr>
<tr>
<td class="pao pao-12">12</td>
<td class="pao"></td>
<td class="pao"></td>
<td class="pao pao-5">5</td>
</tr>
<tr>
<td class="pao pao-11">11</td>
<td class="pao"></td>
<td class="pao"></td>
<td class="pao pao-6">6</td>
</tr>
<tr>
<td class="pao pao-10">10</td>
<td class="pao pao-9">9</td>
<td class="pao pao-8">8</td>
<td class="pao pao-7">7</td>
</tr>
</table>
<br/>
<input type="button" value="开始跑" id="startPao" />
</div>
</body>
</html>
时间： 2024-11-20 11:33:30